Image-sensing display panels with LCD display panel and photosensitive element array

ABSTRACT

A camera comprising various arrangements for employing optical elements in association with photosensitive elements are described. In some of the arrangements, the optical elements are formed integrally with a substrate containing the photosensitive elements. In other arrangements, an optical element is mounted to a package, or the like, containing the substrate and photosensitive elements. In other arrangements, two or more optical elements are employed, including conventional refractive elements, refractive focusing elements, and refractive beam splitting elements. Utility as solid state image sensors is discussed. Utility for monochromatic and color imaging is discussed. Various devices based on such camera arrangements and methods of making same are discussed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.07/954,958, filed on Sep. 30, 1992 by Rostoker, now abandoned.

TECHNICAL FIELD OF THE INVENTION

The invention relates to devices which incorporate display panels, suchas a liquid crystal display (LCD).

BACKGROUND OF THE INVENTION

Modern charge-coupled devices and other photosensitive semiconductordevices (hereinafter "solid state image sensors") are capable ofproviding signals representing images formed (focused) on a surfacethereof. Generally, the surface of a solid state image sensor isprovided with an array (for example, rows and columns) of discretephotosensitive semiconductor elements (for example gates or junctions),and particular array locations correspond to a particular "pixel" (orposition) in the image. Modern video cameras, for example, use discretelens systems (optics) to focus images onto such solid state imagesensors.

Generally, a single "taking" lens is supported at a fixed distance, suchas at least several or tens of millimeters, from the array ofphotosensitive elements, so that an image may be focused onto the array.The array is located at the focal plane of the lens. Additional lenses,in front of the taking lens, provide for focusing and image enlargement.

Binary (diffractive) optical elements are discussed in "Binary Optics",Scientific American, May, 1992, pages 92, 94-97 ("Article"),incorporated by reference herein.

U.S. Pat. No. 4,425,501 discloses a transparent member 20 upon which aplurality of lenslets have been formed. The member is "mounted above"the die 10. Each lenslet is associated with a pair of detectors on thedie.

U.S. Pat. No. 4,553,035 discloses in FIG. 3A two one-dimensional arrays21 of photodetectors juxtaposed to a cylindrical lens 21. Also, as shownin FIG. 14, three rows of one-dimensional sensors may be provided, andred (R), green (G) and blue (B) filters may be installed, wherebysignals of each sensor may be independently read to obtain colorinformation.

U.S. Pat. No 4,636,631 discloses a lens 8 assembled to a wafer 2 on asubstrate 1, with thickness-calibrating shims 6,7 and with a layer ofphotoresist 5.

U.S. Pat. No. 4,733,096 discloses in FIG. 2 a lens structure ("sensorsubstrate" 32; 32a, 32b, 38). An insulating layer 42 is juxtaposed withthe lens structure 32. Sensors 44 are juxtaposed with the insulatinglayer 42.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide an improved solidstate image sensor.

It is a further object of the invention to provide a method of makingsuch an image sensor.

It is a further object of the present invention to provide a solid stateimage sensor with integral optics.

It is a further object to provide solid state image sensors useful forcolor imaging.

It is a further object to provide a method of imaging using a solidstate image sensor.

It is a further object of the present invention to provide an imagingapparatus. In a preferred embodiment, the apparatus comprises a camera.Preferably, the camera includes the solid state image sensor discussedabove.

It is a further object of the present invention to provide a televisioncamera based on the solid-state image sensor discussed above.

It is a further object of the present invention to provide various othercamera and LCD devices based on the solid-state image sensor discussedabove.

According to the invention, an optically-transmissive layer isintegrally formed over a substrate having an array of photosensitiveelements on its surface. The layer is provided with an array oflenslets, preferably binary optics. There is a one-to-one correspondencebetween the lenslets and the photosensitive elements. The lenslets arephysically or virtually offset from the photosensitive elements, so thateach photosensitive element provides a unique pixel of informationcorresponding to a unique position of an incident image. In aggregate,the photosensitive elements provide a complete two-dimensionalrepresentation of the incident image. Further according to theinvention, the photosensitive elements can be arranged in regular,irregular, square or rectangular arrays.

Further according to the invention, the array of photosensitive elementsmay cover substantially the entire underlying substrate, or may coveronly a selected area (e.g., a central area) of the substrate.

Further according to the invention, an opaque masking layer can beinterposed between the lenslet layer and the photosensitive elements,and the masking layer can be provided with holes aligned with thephotosensitive elements. In this manner, light focused by a lenslet thatis not incident on a photosensitive element is prevented from impactingcircuit elements which may be disposed on the substrate between thephotosensitive elements.

Further according to the invention, an optically-transmissive layer maybe interposed between the lenslet-containing layer and thephotosensitive elements. This layer acts as an integral standoff betweenthe substrate and the lenslet-containing layer.

Further according to the invention, both an optically-transmissive and amasking layer can be interposed between the lenslet-containing layer andthe surface of the substrate. The optically-transmissive layer may bedisposed over the masking layer, or vice-versa.

Further according to the invention, various materials and techniques aredescribed for the lenslet-containing layer, the masking layer and theoptically-transmissive (interposed) layer. Further according to theinvention, the lenslets are preferably formed as diffractive (ratherthan as refractive) optical devices.

In an alternate embodiment of the invention, a focusing element issupported by a package body, or the like, above the surface of asubstrate.

Further according to the invention, a first optical element is supportedby a package body, or the like, above the surface of a substrate, and asecond optical element is integrally formed on the substrate. These twooptical elements may cooperate to minimize spherical and/or chromaticaberrations exhibited by either of the optical elements.

Further according to the invention, photosensitive elements are arrangedin closely spaced "triads" (or "triplets"), and the triads are arrangedin an array. An overlying optically-transmissive layer has lensletsformed therein. One lenslet is associated with each triad ofphotosensitive elements. The lenslet is preferably a diffractive devicethat is capable of focusing different wavelengths (e.g., red, green,blue) of incident light onto a particular one of the threephotosensitive elements of a triad.

Further according to the invention, three monochromatic image sensorsare juxtaposed in a linear array, a curved array, or a triangularpattern. An additional optical element serves as a beam splitter, anddirects different wavelengths of incident light onto a particular one ofthe three monochromatic image sensors.

In an embodiment of the invention, a television camera may be provided,comprising a camera housing and an image sensor of the type discussedabove mounted within the camera housing.

According to one feature of the invention, the aforementioned televisioncamera may be provided in a housing mounted to a bracelet-type bandwhich is sized to fit around a human wrist.

According to another feature of the invention, the housing is formedintegrally with at least a portion of a bracelet-type band which issized to fit around a human wrist.

According another feature of the invention, the housing is sized andshaped to facilitate attachment to a telescope eyepiece.

According to another feature of the invention, the housing is sized andshaped to facilitate attachment to a microscope eyepiece.

Another television camera embodiment further comprises a fixed-focusoptical system mounted above the image sensor.

Another television camera embodiment further comprises a variable-focusoptical system mounted above the image sensor.

Various embodiments are directed to a security system based on a cameraof the type discussed above in combination with a video display monitor.

Various other embodiments are directed to a video-phone system basedupon a camera of the type discussed above, a video display monitor, andmeans to transmit and receive a video signal from the camera across acommunications line to the video display monitor.

Further according to the invention, an image-sensing display panelcomprises an LCD display panel; a substrate having an array ofphotosensitive elements disposed on a surface of the substrate, and anoptically transmissive layer above and contiguous with the array,wherein said transmissive layer is capable of focusing light onto saidarray.

According to a feature of the invention, the LCD display panel and thesubstrate are aligned along the same optical path.

According to a feature of the invention, the LCD display panel, theoptically transmissive medium (layer) and the substrate are alignedalong the same optical path.

Other objects, features and advantages of the invention will becomeapparent in light of the following description thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially cut-away, perspective view of the basic solidstate image sensor, according to the present invention.

FIG. 1A is a plan view of the surface of a substrate having an array ofphotosensitive elements, according to the present invention.

FIG. 1B is a plan view of an alternate embodiment of the surface of asubstrate having an array of photosensitive elements, according to thepresent invention.

FIG. 1C is a plan view of an yet another embodiment of the surface of asubstrate having an array of photosensitive elements, according to thepresent invention.

FIG. 2A is a diagrammatic representation of a physical offset betweenlenslets and photosensitive elements, according to the presentinvention.

FIG. 2B is a diagrammatic representation of an alternate embodiment of aphysical offset between lenslets and photosensitive elements, accordingto the present invention.

FIG. 2C is a diagrammatic representation of an embodiment of a virtual(rather than physical) between lenslets and photosensitive elements,according to the present invention.

FIG. 3 is a partially cut-away, perspective view of an alternateembodiment of the invention.

FIG. 4 is a partially cut-away, perspective view of yet anotherembodiment of the invention.

FIG. 4A is a side view of yet another embodiment of the invention.

FIG. 4B is a side view of yet another embodiment of the invention.

FIG. 5 is a perspective view of yet another embodiment of the invention.

FIG. 6 is a cross-sectional view of yet another embodiment of theinvention.

FIG. 7 is a cross-sectional view of yet another embodiment of theinvention.

FIG. 8 is a partially cut-away, perspective view of yet anotherembodiment of the invention.

FIG. 9 is a diagrammatic representation of yet another embodiment of theinvention.

FIG. 9A is a diagrammatic representation of yet another embodiment ofthe invention.

FIG. 9B is a diagrammatic representation of yet another embodiment ofthe invention.

FIG. 10 is a diagrammatic representation of yet another embodiment ofthe invention.

FIG. 11 is a cross-sectional representation of yet another embodiment ofthe invention.

FIG. 12 is a cross-sectional representation of yet another embodiment ofthe invention.

FIG. 13 is a cross-sectional view of a television camera incorporating asolid-state image sensor according to the invention.

FIG. 14A is a block diagram of a security system incorporating a solidstate image sensor according to the invention.

FIG. 14B is a block diagram of a video-telephone system incorporating asolid state image sensor according to the invention.

FIG. 15 is a partially diagrammatic, partially schematic view of acombined display and solid state image sensor arrangement.

FIGS. 16A-16C are cross-sectional views of various "sandwiched" displayand solid-state image sensor arrangements, according to the invention.

FIG. 16D is a block diagram of a multiplexing system for simultaneousdisplay and image capture, according to the invention.

FIGS. 17A-16C are views of various embodiments of combined display andimage sensor arrangements affixed to a bracelet-type band, according tothe invention.

FIG. 18 is a block diagram of a 2-way audio/video communication device,according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 show a solid state image sensor 100. A plurality ofphotosensitive elements 102 (shown as dots " ") are formed on the frontsurface (up, in the figure) of a substrate 104. The photosensitiveelements 102 may be memory cells which discharge upon incidence oflight, a CCD array, or any other suitable device which changes state orgenerates a potential or potential difference upon incidence of light.The substrate 104 may be a silicon semiconductor die. Other suitablesemiconducting materials may also be used. The photosensitive elements102 are arranged in an array of hundreds or thousands of rows andcolumns (only six rows and columns shown, for clarity). Preferably, thephotosensitive elements are arranged in a square (m×m) or rectangular(m×n) array of evenly spaced elements. However, the photosensitiveelements of one row (or column) can be offset from the elements of anadjacent row (or column). In FIG. 1A, the photosensitive elements 102are arranged in a square array, and are arranged in columns and rows. InFIG. 1B, the photosensitive elements 102' are arranged in a rectangulararray on the surface of a substrate 104', and the photosensitiveelements 102' of one row (or column) are offset from the photosensitiveelements 102' of adjacent rows (or columns).

Returning to FIG. 1, an optically-transmissive layer 106 is applied overthe substrate, covering at least the entire array of elements 102 (or102', or 102" discussed hereinbelow). Although the elements 102 areshown covering substantially the entire surface of the substrate, it iswithin the scope of this invention that the array of elements occupiesonly a selected area, such as a central area 103 (dashed lines), of thesubstrate 104", as shown in FIG. 1C, where the photosensitive elements102" cover only a central area 103 of the substrate 104".

In FIG. 1A, the photosensitive elements of one row are aligned with thephotosensitive elements of an adjacent row, and the photosensitiveelements of one column are aligned with the photosensitive elements ofan adjacent column.

In FIG. 1B, the photosensitive elements of one row are offset from(located orthogonally between) the photosensitive elements of anadjacent row, and the photosensitive elements of one column are offsetfrom the photosensitive elements of an adjacent column.

Returning to FIG. 1, the layer 106 is formed of a suitablyoptically-transmissive material such as silicon dioxide (SiO₂), spin-onglass, re-flow glass, photoresist, spin-on photoresist, re-flowphotoresist, or the like, and is preferably of substantially uniformthickness. Spin-on and re-flow techniques provide relatively uniformthickness layers. In the event that the thickness of the layer 106 isnon-uniform, as initially applied, it is preferably planarized bychemical-mechanical polishing techniques, or the like. For a descriptionof chemical-mechanical polishing techniques, see (e.g.) U.S. Pat. Nos.4,671,851, 4,910,155 and 4,944,836, incorporated by reference herein.

Alternatively, the layer 106 can be applied as a sedimentary layer ofrelatively uniform thickness, as discussed in commonly-owned, co-pendingU.S. patent application Ser. No. 906,902, entitled SEDIMENTARYDEPOSITION OF PHOTORESIST ON SEMICONDUCTOR WAFERS, filed Jun. 29, 1992by Rostoker.

The thickness of the layer can be verified by optical interferencetechniques, or the like, and adjusted to an appropriate final thickness.

As shown in FIG. 1, the layer 106 is provided with a plurality of lenselements, or "lenslets" 108 (shown as circles "O"). The lens elements108 are arranged in an array of hundreds or thousands of rows andcolumns (only six rows and columns shown, for clarity), corresponding ona one-to-one basis to the underlying elements 102. The lenslets (lenselements) 108 are aligned over the photosensitive elements 102 in one ofvarious ways discussed hereinbelow. Preferably, the lens elements 108are formed as diffractive (binary) optical structures, but may be anylens or optical device which is capable of focusing an image onto theunderlying photosensitive elements 102.

Although each lenslet 108 is generally directly over a correspondingphotosensitive element 102, each pair of lenslets and correspondingphotosensitive element is specifically arranged to sense a particularportion of an image being focused onto the substrate. This isaccomplished in one of a variety of ways.

FIG. 2A shows an arrangement 200 of three lens elements 108a, 108b and108c, over three corresponding photosensitive elements 102a, 102b and102c. In this example, the photosensitive elements are arranged in aregular array, with constant spacing "d" therebetween. (This figureillustrates only three photosensitive elements and lens element.)However, the lens elements are arranged in an irregular array, withvarying spacing. More particularly, the lens element 108a is physicallyoffset in one or two dimensions from the photosensitive element 102a.The lens element 108b is physically aligned with (directly over) thephotosensitive element 102b. The lens element 108c is physically offsetin an opposite (from the offset of 108a) direction from thephotosensitive element 102c. In this manner, specific portions (e.g.,top left, center, bottom right, etc.) of an image being focused onto thesubstrate can be focused onto specific photosensitive elements 102. Eachphotosensitive element 102 will provide information relating to one"pixel" of the image being focused onto the substrate. In aggregate, theplurality of photosensitive elements will provide pixel information forthe entire image of interest--each pixel representing a particularlocation on the image. The various physical offsets of the lens elementsare arranged to effect this result, namely by covering the entire twodimensional field of the image.

FIG. 2B shows an alternate arrangement 210 of three lens elements 108d,108e and 108f, over three corresponding photosensitive elements 102d,102e and 102f. In this example, the lens elements are arranged in aregular (evenly spaced) array, with constant spacing "s" therebetween.However, the photosensitive elements are arranged in an irregular(varying spacing) array. More particularly, the photosensitive element102d is physically offset in one or two dimensions from the lens element108d. The photosensitive element 102e is physically aligned with(directly under) the lens element 108e. The photosensitive element 102fis physically offset in an opposite (from the offset of 102e) directionfrom the lens element 108f. In this manner, specific portions (e.g., topleft, center, bottom right, etc.) of an image being focused onto thesubstrate can be focused onto specific photosensitive elements 102. Eachphotosensitive element 102 will provide information relating to one"pixel" of the image being focused onto the substrate. Again, inaggregate, the plurality of photosensitive elements will provide pixelinformation for the entire image of interest--each pixel representing aparticular location on the image. The various offsets of thephotosensitive elements are arranged to effect this result, namely bycovering the entire two dimensions of the image. FIG. 2C shows analternate arrangement 220 of three lens elements 108g, 108h and 108i,over three corresponding photosensitive elements 102g, 102h and 102i. Inthis example, the lens elements are arranged in a regular array, withconstant spacing "s" therebetween, and the photosensitive elements arearranged in a regular array with constant spacing "d" therebetween. Inother words, the lenslets are all physically aligned with the underlyingphotosensitive elements, with no physical offset. In the event that allof the lenslets 108g, 108h and 108i were formed the same (same focusingparameters) as one another, this would result in all of thephotosensitive elements 102g, 102h and 102i providing the same pixelinformation as the remaining photosensitive elements. Therefore, thelens elements 108g, 108h and 108i are each formed as binary(diffractive) optics, with unique focusing characteristics. Moreparticularly, the lenslet 108g is formed with its focal point offset inone or two dimensions from the photosensitive element 102g. The lenslet108h is formed with its focal point aligned with the photosensitiveelement 102h. The lenslet 108i is formed with its focal point offset inan opposite direction (vis-a-vis the lenslet 108g) from thephotosensitive element 102e and is physically aligned with the lenselement 102i. This provides a "virtual" offset for each pair of lensletsand photosensitive elements, in marked contrast to the "physical"offsets described with respect to FIGS. 2A and 2B. However, the resultis similar in that, specific portions (e.g., top left, center, bottomright, etc.) of an image being focused onto the substrate can be focusedonto specific photosensitive elements 102. Each photosensitive element102 will provide information relating to one "pixel" of the image beingfocused onto the substrate. Again, in aggregate, the plurality ofphotosensitive elements will provide pixel information for the entireimage of interest--each pixel representing a particular location on theimage. The various virtual offsets are arranged to effect this result,namely by covering the entire two dimensions of the image.

The commonality between the arrangements of FIGS. 2A, 2B and 2C is thatthe relative orientation (whether physical or virtual or in combination)of the lenslets and photosensitive elements is arranged so that lightfrom a selected portion of an image being focused by the lenslets ontothe substrate is focused onto only one of the photosensitive elements,and in aggregate the photosensitive elements of the array provide acomplete pixel-by-pixel image (i.e., signals representative of theincident image).

In the arrangements 200, 210 or 220 of FIGS. 2A 2B or 2C, light from aparticular portion of an image being focused onto the die (substrate)is, however, focused by all of the lens elements 108 onto the substrate.However, the light from a particular portion of the image is focusedonto only one of the photosensitive elements 102. For the remainder ofthe photosensitive elements 102, the light from that particular portionof the image is focused onto the front surface of the substrate in areasbetween photosensitive elements 102. It is within the scope of thisinvention that there may well be circuitry (e.g., image processingcircuitry) formed on the front surface of the substrate in the areasbetween photosensitive elements 102 or in any other appropriate areas.Such circuitry may be adversely affected by light. Hence, these areasbetween photosensitive elements are preferably "masked" with an opaquelayer, such as silicon nitride, aluminum or opaque photoresist (ink).

FIG. 3 shows an arrangement 300 similar to that of FIG. 1. However, inthis example, a optically-opaque layer 310 is applied over the substrate304, and over any circuit elements (not shown) on the surface of thesubstrate. The layer 310 is formed of any suitable material, such assilicon nitride, opaque photoresist, or the like, and is applied so asto have openings 312 (holes) in registration with the plurality ofphotosensitive elements 302 on the surface of the substrate. As in FIG.1C, the array of photosensitive elements may cover only a portion of thesurface of the substrate. An optically transmissive layer 306 is appliedover the masking layer 310, and can be applied to fill the holes whilemaintaining a relatively planar surface. The layer 306 can also bechemical-mechanically polished prior to forming lenslets in its exposedsurface. Lenslets 308 (preferably diffractive) are formed (or deposited)in the optically transmissive layer. The techniques discussed withrespect to FIGS. 1A, 1B, 2A, 2B and 2C are applicable with thisarrangement which uses an additional masking layer 310.

In certain applications, it may be desirable to space the lens elements(e.g., 108, 308) further away from the photosensitive elements (e.g.,102, 302), while maintaining the integral structure of the substrate,photosensitive elements, masking layer (if used) and lens elements. Thiswill allow greater flexibility in the design of the lenslets, such asincreased depth of focus.

FIG. 4 shows an arrangement 400 similar to that of FIG. 1. However, inthis example, an optically-transmissive layer 410 is applied over thesubstrate 404, and over any circuit elements (not shown) on the surfaceof the substrate. The layer 410 is preferably applied with uniformthickness, compensating for topological non-uniformities that may becaused by the underlying photosensitive elements (not shown) on thesurface of the substrate. The layer 410 is formed of any suitablyoptically-transmissive material, such as silicon dioxide (SiO₂), spin-onglass, re-flow glass, photoresist, spin-on photoresist, re-flowphotoresist or the like, and is preferably of substantially uniformthickness. Spin-on and re-flow techniques provide relatively uniformthickness layers. In the event that the thickness of the layer 410 isnon-uniform, as initially applied, it is preferably planarized bychemical-mechanical polishing techniques, or the like. Alternatively,the layer 410 can be applied as a sedimentary layer of relativelyuniform thickness, as discussed hereinabove.

Whereas in FIG. 3, the layer 310 acted as a masking layer, to preventlight focused away from a photosensitive element from impacting oncircuit elements between photosensitive elements, in this example, thelayer 410 acts as a "standoff" to establish a suitable (increased)spacing for the overlying layer 406 containing lenslets 408.

As in FIG. 1C, the array of photosensitive elements in the arrangement400 may cover only a portion of the surface of the substrate. Further,the techniques discussed with respect to FIGS. 1A, 1B, 2A, 2B and 2C areapplicable with the spacing layer 410.

FIG. 4A shows an arrangement 420 wherein the teachings of FIGS. 3 and 4are applied in combination. In this example, a masking layer 422(similar to 310) is applied over the substrate 404', with holes (notshown) aligned with the photosensitive elements (not shown). Anoptically-transmissive standoff layer 424 (similar to 410) is appliedover the masking layer 422. An optically-transmissive layer 406' isapplied over the optically-transmissive standoff layer 424, and isprovided with lenslets (not shown). The techniques discussed withrespect to FIGS. 1A, 1B, 1C, 2A, 2B and 2C are applicable in thisarrangement 420.

FIG. 4B shows an arrangement 440 wherein the teachings of FIGS. 3 and 4are applied in combination. In this example, an optically-transmissivestandoff layer 444 (similar to 410) is applied over the substrate 404".An opaque masking layer 442 (similar to 310) is applied over thestandoff layer 444, and has holes aligned with the photosensitiveelements (not shown). An optically-transmissive layer 406" is appliedover the masking layer 442, and is provided with lenslets (not shown).The techniques discussed with respect to FIGS. 1A, 1B, 1C, 2A, 2B and 2Care applicable in this arrangement 420.

Having created a sizeable spacing between the lens elements (e.g., 108,308, 408) and the photosensitive elements (e.g., 102, 302, 402),alternative and additional arrangements of lens elements can beimplemented.

FIG. 5 shows an arrangement 500 wherein a single, large lens element 508is formed in an optically-transmissive layer 506 overlying an array ofphotosensitive elements 502 on a substrate 504. Preferably, the lenselement 508 is formed as a single binary (diffractive) optical device,covering the entire array of photosensitive elements 502. The techniquesdiscussed with respect to FIGS. 1A, 1B, 1C, 3, 4, 4A and 4B areapplicable in this arrangement 500. Preferably, anoptically-transmissive layer (not shown) is interposed between thesingle large lens element 508 and the surface of the substrate 504(compare the optically-transmissive layer 410 of FIG. 4).

FIG. 6 shows an arrangement 600 where the lens element 608 is notintegral with the substrate (as it was in the previousembodiments/arrangements). Rather, in this arrangement, a lens element608 is mounted to vertical spacing members such as pins, posts, shims,or the side walls 622 of a package 620, or the like, containing thesubstrate 602 (array of photosensitive elements not shown). The sidewalls 622 of the package body establish a known standoff for the lenselement (i.e., distance between the lens element and the photosensitivearray on the surface of the die). With the substrate 602, and thephotosensitive array located in a predetermined location between theside walls 622, an accurate X-Y alignment of the lens 608 over thephotosensitive array occurs. The lens element 608 is preferably arefractive optic, similar to those described above (e.g., 108, 308, 408,508), but in this case is non-integral with the substrate. Further, thetechniques discussed with respect to FIGS. 1A, 1B, 1C, 2A, 2B and 2C areapplicable in this arrangement 600.

It is within the scope of this invention to provide "mixed" opticscomprising a combination of conventional (including refractive) lensesand binary refractive or diffractive lenses. For example, the lenselement 608 can be formed as a conventional refractive lens which isalso etched with a diffractive optical pattern. Such combination lensarrangements could be used in any lens application (e.g. , 108, 208,308, 408, 508).

FIG. 7 shows an arrangement 700 similar to that of FIG. 6, in that alens element 708 is supported above the substrate 702 by verticalpillars or posts/pins/shims, such as the side walls 722 of a package 720(similar to 620), or the like. (The photosensitive array on the frontsurface of the die/substrate is not shown.) However, the substrate isalso provided with an integral optic 788 on its front surface. Twovariations are possible: (1) the lens element 708 can be a conventionalrefractive lens, and the substrate-integral optic 788 can be similar toany of the above-described diffractive elements (e.g., 108, 308, 408,508), or (2) the lens element 708 can be similar to any of theabove-described diffractive elements (e.g., 108, 308, 408, 508), and thelens element 788 can be a conventional refracting lens mounted to thesurface of the substrate. Additionally, either lens element 708 or 788may be a combination lens of conventional cum binary or conventional cumrefractive lenses. Further, the techniques discussed with respect toFIGS. 1A, 1B, 1C, 2A, 2B and 2C are applicable in this arrangement 600.In this manner, the "mixed" optics 708 and 788 can be designed toeliminate spherical and/or chromatic aberration. Filters may also beused to remove light having a wavelength subject to chromatic aberrationand not otherwise corrected for by the use of "mixed optics".

The preceding arrangements are generally best suited for monochromaticimaging. There also exists a viable requirement for color imaging. Colorimaging is typically accomplished with three optical systems, eachresponsive to a different color of light, such as red (R), green (G) andblue (B). Each system comprises a lens, a filter and an associatedphotodetector (array). Such triplication of elements is, evidently,costly compared to a single system.

FIG. 8 shows an arrangement 800 suited for color imaging. An array ofphotosensitive elements 802 are arranged on the front surface of asubstrate 804, in a manner similar to the photosensitive elements 102(e.g.). However, in this arrangement 800, at each array location, thereare three closely-grouped together photosensitive elements ("triplets")802a, 802b, 802c, rather than a single photosensitive element 102. A 4×4array is shown, for illustrative clarity. An optically-transmissivelayer 806 (similar to 106) is formed over the array of photosensitiveelement triplets. In this case, there is one lenslet 808 for each"triplet" of photosensitive elements. The lens elements are preferablyformed as diffractive elements (or a combination lens), and are designedto have different focal points for different wavelengths of light. Forexample, red (R) light can be focused onto the element 802a of atriplet, green (G) light can be focused onto the element 802b of thetriplet, and blue (B) light can be focused onto the element 802c of thetriplet. In this manner, color imaging can be achieved. The techniquesdiscussed above, with respect to offsets (so that each tripletrepresents a pixel of the incident image), masking and transparentlayers interposed between the lens element layer (806) and thesubstrate, supporting the lens structure or another lens structure on apackage or the like, providing "mixed" optics, etc., are applicable tothe technique of grouping three photosensitive elements at each array(pixel) location.

FIG. 9 shows an alternate arrangement 900 of a color capable solid stateimage sensor. Whereas the arrangement of FIG. 8 employed a singlesubstrate (die), and triplets of photosensitive elements, in thisarrangement 900, three solid-state image sensors 902, 904, 906 areemployed, each of which is suited to monochromatic image sensing. Eachimage sensor 902, 904, 906 is formed in a manner similar to the sensor100 of FIG. 1 (and the enhancements to the FIG. 1 embodiment, discussedhereinabove, are equally applicable). An image 910 ("A") is focused byany suitable optics (not shown) through a beam splitter 912. The beamsplitter 912 is preferably a diffractive optic that is designed todirect different wavelengths of light at different angles. For example,the beam splitter 912 directs red (R) light towards the sensor 902,directs green (G) light towards the sensor 904, and directs blue (B)light towards the sensor 906. The beam splitter 912 can be designed toaccommodate a linear, planar arrangement of sensors 902, 904, 906, asshown. Alternatively, the three sensors 902', 904' and 906' can bearranged in a planar, triangular (e.g., equilateral) pattern, as shownin FIG. 9A, so that the angles to each of the sensors from the beamsplitter 912' are preferably, but not necessarily equal but differentlyoriented. Alternatively, the three sensors 902", 904", 906" can bearranged in a curved, linear array, as shown in FIG. 9B, so that thedistance from the beam splitter 912" to each of the sensors is the sameto produce equivalent imaging (else, suitable correlation of data can bedone if the distances are varied). The distance can correspond to thefocal length (in the usual sense of the term) of the lens.Alternatively, the distance can be sufficient to permit a predeterminedmapping of the image onto the sensors. The mapping may be either aone-to-one mapping or may instead be sufficient to be used incombination with a compression or decompression algorithm. The term"focal length" as defined herein for each of the embodiments of thepresent invention should be construed to include both of thesedefinitions, and specifically to include the distance necessary toproduce a focal plane image with one-to-one correspondence with a"viewed" object, in addition to the usual meaning of the term "focallength."

The three sensors of any of these embodiments (FIGS. 9, 9A, 9B) can bearranged on any suitable mounting substrate. For example, the threesensors of FIGS. 9A and 9B can be disposed in a package similar to thatof FIGS. 6 or 7. For example, the optical element 708 of FIG. 7 couldfunction as a beam splitter (912), and three sensors, each having itsown integral focusing optic could be disposed within the cavity of thepackage (each in a manner similar to 702/788).

FIG. 10 shows a chip 1000 including an image sensing array 1001. In thepreferred embodiment shown in FIG. 10, the chip also includes a logicarray 1002 for processing the signals generated by the array 1001. Thechip may also include a memory array 1003 for storing signals generatedby array 1001 or array 1002. The logic array 1002 and/or memory array1003 can be an embedded array as described in, e.g., U.S. patentapplication Ser. No. 07/596,680. In one embodiment, the memory array1003 can be a "cache memory."

FIG. 11 shows a cross-sectional view of a method of forming a chip inaccordance with an embodiment of the present invention. A substrate 1104is coated successively with a first optically transmissive layer 1103,such as spun-on glass, a second optically transmissive layer 1102, suchas pyrolitic silicon dioxide, and a layer of photoresist 1101. Thephotoresist 1101 is exposed and developed by conventional techniques.The photoresist 1101 is then used as a mask to etch second opticallytransmissive layer 1102. Any suitable etching technique can be used.Preferably, reactive ion etching is used when vertical sidewalls aredesired. Wet chemical etching may also be used, alone or in combinationwith reactive ion etching, to create more rounded geometries whereappropriate. In a preferred embodiment, a laser beam is used to improvethe shape of the lens, and to correct any defects in the lens shapewhich may be detected during testing. If desired, the entire lens may beshaped by the use of the laser. This avoids the need for masking andetching, but reduces throughput.

Diffractive lenses for use in accordance with the present invention maybe produced by any suitable technique. In one embodiment of the presentinvention, such lenses are shaped by chem-mech polishing or etching.

The result is shown in FIG. 12. In FIG. 12, layer 1202 represents thesecond optically transmissive layer after the coating and etching step.In this Figure, layer 1202 has been formed into a fresnel or binary lensstructure. The first optically transmissive layer 1203 provides a gapbetween the substrate 1204 which permits the lens 1202 to focus an imageon an appropriate area of the substrate 1204 having one or more imagesensing devices.

FIG. 13 is a cross-sectional view of a television camera 1300,incorporating a solid state image sensor 1310 of the type describedhereinabove. Any of the solid-state image sensors described hereinaboveare suitable in this arrangement, for example, 300 as describedhereinabove with respect to FIG. 3. The image sensor 1310 is mountedwithin a housing 1320, and provides a video output signal 1312. Avariable focus optical system 1330 is mounted to the housing 1320 overthe solid-state image sensor 1310. Because of the small size of thesolid-state image sensor, it is possible to provide an extremely smallcamera capable of application in very tight spaces or in applications,such as security systems, where it may be desirable that the camera behidden.

The variable focus optical system 1330 is shown having one or morelenses, such as lenses 1340 and 1350, which may be conventional, binary,or other refractive or diffractive or combination lenses, with a slidingsystem 1360, well known in the camera technology, to vary the focallength. Other means for varying the focal length are contemplated.

The variable focus optical system 1330 is not essential to the operationof the television camera 1300, since the solid-state image sensorsdescribed herein have built-in optical systems providing fixed-focus.However, the variable focus optical system 1330 permits alteration ofthe basic focal length of the solid-state image sensor 1310 and providesa wider range of distances over which the camera 1300 will operateeffectively.

Such a camera 1300 may also be equipped with an aperture control 1380(such as an iris) to control the intensity of light transmitted to theimage sensor. Alternatively, or in combination, circuitry could beutilized with the image sensor to enhance or subdue sensitivity tovariable ambient light characteristics about the camera/sensor.

Alternatively, a fixed-focus optical system (such as in FIG. 13, butwithout the sliding system 1360) could be substituted for the variablefocus optical system 1330 to provide a different focal length than thatprovided by the solid-state image sensor for such specializedapplications as dedicated inspection systems, microscope cameras,telescope cameras, etc..

FIG. 14A is a block diagram of a basic security system comprising atelevision camera 1410a of the type (1300) described with respect toFIG. 13 and television monitor 1430a. A video signal 1420 representingan image "seen" by the camera 1410a is connected to the monitor causinga representation of the image to be displayed on the monitor 1430a. Anintermediate memory or processor may be utilized to store or modify thesignal 1420 prior to display. The extremely small camera size affordedby the application of a solid-state image sensor permits applicationsinvolving location and positioning of the camera 1410 in places whichmight otherwise be difficult or impossible.

FIG. 14B is a block diagram of a video-telephone system 1400b comprisinga camera 1410b of the type (e.g., 1300) described hereinabove withrespect to FIG. 13, a transmitting line interface 1440b, a receivingline interface 1440b, and a television monitor 1430b. A video signal1420b from the camera 1410b is interfaced to and transmitted over acommunication line 1450b by the transmitting line interface 1440b. Thecommunication line 1450b may be, for example, a dialed telephoneconnection across a commercial switched telephone network. The receivingline interface 1440b converts the signal received over the communicationline back into a video signal and transmits it through line 1460b (forpossible storage by memory and/or signal processing--not shown) beforeor after is may be displayed on the monitor 1430b.

The foregoing discussions have been concerned primarily with solid-stateimage sensors and applications thereof. The following discussion withrespect to FIGS. 15, 16A-D, and 17A-C are directed to combinedarrangements of solid-state image sensors and LCD display panels. Thesecombined arrangements are effectively image-sensing display panelscapable of both image display and image capture. LCD panels, for displaypurposes, are well known.

FIG. 15 is a view of a combined display and image sensor 1500. A solidstate image sensor 1510 ("camera") providing a "Camera" output signal1515 (video signal) and an LCD (Liquid Crystal Display) Panel (Display)1520 are mounted side-by side on a common substrate (backing) 1530. TheLCD may alternatively be a plasma screen display or other suitabledisplay means for the purpose, all included in the term "LCD" or "LiquidCrystal Display". An electrical interface 1525 to the LCD panel 1520provides data to be displayed on the LCD panel. The "camera" outputsignal 1515 is an electrical analog of the image "seen" by thesolid-state image sensor 1510.

FIGS. 16A is a view of a sandwiched display/image sensor arrangement. Abinary optic element 1610 (e.g., lens element 788, FIG. 7) or acombination lens element is disposed over an array of photo-sensitiveelements 1620 (e.g., 702, FIG. 7 or 802, FIG. 8). These two elements aredisposed over an LCD display panel 1630. The binary optic element 1610and array of photo-sensitive elements 1620, in combination, form animage sensor. The image sensor, via the array of photo-sensitiveelements 1620, produces a video output signal 1640, representative of animage "seen" by the array 1620. The LCD display panel 1630 is responsiveto signals on an LCD electrical interface 1650 to produce a visibleimage. The binary optic element 1610 and array of photo-sensitiveelements 1620 are sufficiently transmissive of light that an imagedisplayed on the LCD display panel 1630 may be seen through them by anobserver. The visibility of the image on the LCD display panel may beaugmented through the use of back-lighting means 1660 (light shown asarrows )) such as an electro-luminescent panel ("EL" panel) orfluorescent lighting tubes.

FIG. 16B is a view of another embodiment 1600b of a sandwicheddisplay/image sensor arrangement, similar to that described with respectto FIG. 16A. All of the same elements (binary or combination opticelement 1610, photo-sensitive array 1620, and LCD display panel 1630)are employed in this display/image sensor arrangement 1600b, but arearranged in a different order. In this embodiment, the LCD display panel1630 overlies the binary optic element 1610, which in turn overlies thephoto-sensitive array 1620. As is known in the art, an LCD panel (e.g.1630) can be made to be either selectively opaque or transmissive oflight, depending upon signals applied thereto via its electricalinterface (e.g., 1650). By causing the display panel 1630 to betransmissive of light (transparent) by applying appropriate electricalsignals via the electrical interface 1650, sufficient light reaches thephoto-sensitive array to cause an image to be formed thereupon. Thisimage is then converted by the photo-sensitive array 1620 into anelectrical video signal 1640 which is representative of the image. It isalso possible, by making the LCD panel 1630 opaque, to block light tothe photo-sensitive array 1620, thereby blocking any image which wouldotherwise be formed thereupon. Additionally, through memory orprocessing means (not shown) described previously, the LCD panel 1630may display a separate image than what is being viewed by thephotosensitive array 1620.

As in the embodiment of FIG. 16A, signals provided to the LCD panel 1630over the LCD electrical interface 1650 permit an image to be formed onthe LCD panel in the form of opaque and transmissive areas on the LCDpanel. The viewability of this image may be augmented by back-lightingmeans 1660. Such systems, shown in FIGS. 16A-C, could also display incolor with color LCD panels or the like in combination with, forexample, a color photo-sensitive array system (e.g., 800, FIG. 8).

FIG. 16C is a view of another embodiment 1600c of a sandwicheddisplay/image sensor arrangement, including means 1660 forback-lighting. In this embodiment 1600c, the binary optic element 1610overlies the LCD panel 1630, which in turn overlies the photo-sensitivearray 1620. The binary optic or combination element 1610 is sufficientlytransmissive of light that an image formed on the LCD panel 1630 may beviewed through the binary optic element 1610. The LCD panel 1630 can bemade sufficiently transmissive of light (by application of appropriatesignals to the LCD electrical interface 1650) to permit an image to beformed through the binary optic element 1610 and LCD panel 1630 onto thephoto-sensitive array 1620. The back-lighting means 1660, enhances theviewability of any image on the LCD panel 1630.

For the sandwiched display/image sensor arrangements 1600a-1600cdescribed hereinabove, it is possible, by multiplexing the operation ofthe LCD display panel 1630 and the photo-sensitive array 1620, tosimultaneously display a viewable image on the LCD display panel 1630and to capture and transmit an image formed on the photo-sensitive array1620. This is accomplished by rapidly alternating the LCD display panel1630 between displayed image and a transparent (transmissive) state viathe LCD electrical interface 1650. For the embodiments of FIGS. 16B and16C (1600b and 1600c, respectively), the video signal 1640 is monitoredonly when the LCD display panel 1630 is in its transparent state. Thealternation of the LCD display panel 1630 occurs at a rate sufficientlyhigh that a human observer does not notice any significant "flicker" ofthe image. For the embodiment of FIG. 16A (1600a) the display may bemonitored when the display is in either state.

Any of the three embodiments may employ back-lighting (e.g., 1660, FIG.16C), but back-lighting will generally interfere with the operation ofthe photo-sensitive array 1620. As a result, it is necessary to "turnoff" the back-lighting means 1660 while the video signal 1640 from thephoto-sensitive array 1620 is being monitored. The embodiment of FIG.16A (1600a) provides a convenient method for accomplishing this. Sincethe LCD display panel 1630 is behind the photo-sensitive array 1620,placing the LCD display panel 1630 into a completely opaque state wouldcause any light from back-lighting means (e.g., 1660) placed behind theLCD-display panel 1630 to be blocked. In this way, the LCD display panel1630 acts as a sort of "shutter" between a back-lighting means and thephoto-sensitive array 1620.

In this case, the back-lighting means would remain "on", and the LCDdisplay panel 1630 would be caused to alternate between a displayedimage and an opaque state. The video signal 1640 from thephoto-sensitive array would then be monitored only when the LCD displaypanel 1630 is in the opaque state.

Alternatively, the LCD display panel 1630 can be selectively darkened(by pattern or "gray-scale") to limit the light that would impinge onthe photo-sensitive array 1620 as another "shutter" means or lightintensity control means where the panel 1630 is in front of the array1620 (e.g., FIG. 16B and 16C).

It is also possible to provide an LCD display panel 1630 which, in itsopaque state, blocks light frequencies which are visible to the humaneye, but passes some light frequencies (e.g., infra-red) which areoutside of the range of frequencies visible to humans. An optical filtermay be employed to limit the light frequency response of thephoto-sensitive array 1620. By using a photo-sensitive array 1620 whichis made sensitive only to those frequencies passed by the LCD array 1630which are not visible to the human eye, it is not necessary to alternatethe LCD image, eliminating "flicker" entirely.

Further, if the photo-sensitive array 1620 is insensitive to the lightfrequency or frequencies produced by the back-lighting means 1660, thenit not necessary to modulate (switch on and off) the backlighting means1660 while the photo-sensitive array is capturing an image.

FIG. 16D is a block diagram of an arrangement for accomplishing thisalternating, multiplexed operation of a sandwiched display/image sensorarrangement 1600d. Any of the three aforementioned sandwicheddisplay/image sensor arrangements 1600a-1600c may be used. Amultiplexing circuit 1670 receives image data 1655 to be displayed onthe LCD display panel 1630, and causes the LCD display panel 1630 toalternate between displaying the image and assuming either a transparentstate (as described above with respect to 1600b or 1600c) or an opaquestate (as describe above with respect to 1600a). The multiplexingoperation is controlled by a synchronizing multiplex control signal1690, which governs the rate and duty cycle at which the transparent (oropaque) state is assumed by the LCD display panel 1630. This samemultiplex control signal 1690 is used to control when the video signal1640 from the photo-sensitive array 1620 is monitored, so that the videosignal 1640 is only "filtered" by the multiplexing circuit 1670. The"filtered" video signal is output by the multiplexing circuit 1670 asimage sensor data 1645.

For large sandwiched display/image sensor arrangements, a large glass,ceramic or plastic may be used for the substrate of the photo-sensitivearray, and the photo-sensitive elements may be disposed thereupon. Thispermits image sensor arrays of arbitrary size to be fabricated.Additionally, with all photo-sensitive elements as well as logic andmemory circuit elements disposed on the display substrate, an efficientlight-weight and easily manufactured system may be developed.

Alternatively, the substrate may be formed by depositing amorphous orpoly-silicon on a continuous sheet of metal, such as aluminum.Techniques similar to this are currently employed in the production ofphoto-voltaic cells.

One embodiment of this type involves sizing and shaping such a largesandwiched display/image sensor arrangement to approximately match thesize and shape of a "sheet" (of, e.g., 8.5 inch by 11 inch paper). Theeffective focal length and aim of the integral optically transmissiveelement (e.g., binary optics) would be provided such that an "image" ofan object, such as a "sheet" of paper would be "seen" by the imagesensor portion of the arrangement, permitting an electronic picture tobe taken of the object. A sheet of paper could be held (or laid)directly on the image-sensing panel. This would provide a page-sizedreader (such as optical character recognition (OCR) readers or graphicsreaders) in the same device as the display for computer systems and thelike.

FIGS. 17A-C are views of various embodiments of a bracelet-mounteddisplay/image sensor arrangement.

FIG. 17A is a view of an arrangement 1700a whereby a solid-state imagesensor 1720 and an LCD display panel 1730 are mounted to a mountingsurface 1725 attached to a bracelet-type band 1710, sized and shaped tofit around a human wrist. Alternatively, a clothes-pin or clip devicemay be used to hold the display/camera devices (1720, 1730). A housing1740 with an optically transmissive element 1750 covers the LCD displaypanel 1730 and the solid-state image sensor 1720. The opticallytransmissive element may be a non-refractive element (e.g., a sheet ofglass, quartz crystal, or transparent acrylic) or a refractive ordiffractive or combination element (lens). Electronic control circuitry(not shown), which is powered (not shown) as by a battery, controls theoperation of the LCD display panel 1730 and solid-state image sensor1720.

FIG. 17B is a view of another similar arrangement 1700b, this timeemploying a sandwiched display/image sensor arrangement 1735. Electroniccircuitry (not shown), such as that described hereinabove, controls theoperation of the display/image sensor arrangement 1735. The arrangement1735 may be of the forms shown in FIGS. 16A-C as 1600a, 1600b, or 1600cand may be backlighted.

FIG. 17C is a view of another similar embodiment 1700c, wherein abracelet-type band 1710a has an integrally formed housing and mountingsurface 1745. The optically transmissive element 1750 mounts directly tothe bracelet-type band over the sandwiched display/image sensorarrangement 1735. As before, electronic circuitry (not shown), controlsthe operation of the display/image sensor arrangement 1735.Additionally, if the upper surface of the arrangement 1735 (or sensor1720 and/or panel 1730) are sufficiently rugged, no upper element (orlens) 1750 may be needed.

The wrist band type sensor of FIGS. 17A-C would be suitable, withattendant communication circuitry, a microphone, audio-capturecircuitry, audio reproduction circuitry and a speaker to be useful as a"Dick Tracy" type watch, enabling voice and picture communication, e.g.,through a cellular phone system or other wireless communication means.Alternatively, such would be an excellent input and output device for,e.g., a computer or security system and could be connected to suchsystem.

FIG. 18 is a block diagram of such a two-way voice and picture(audio/video) communication system. A first audio/video communicationdevice 1800a, of the type mentioned above (e.g., "Dick Tracy" watch)transmits and receives communication signals 1820 over a wirelesscommunition medium via a wireless communication circuit 1820, (e.g., acellular telephone circuit). A camera chip 1802 of the type describedhereinabove and an LCD display panel 1804, provide means 1801 for imagecapture and display. An image-sensing display panel of the typedescribed hereinabove (e.g., 1600a, 1600b, or 1600c, FIGS. 16A-C) may beused to provide the camera 1802 and the LCD display panel 1804 in asingle integral unit (1801). Camera and LCD control circuitry 1806provides means for processing electrical signals 1805 from the camera1802 and provides electrical signals 1803 to the LCD display 1804. Anaudio circuit 1814 connects to the wireless communication circuit 1808,excahnging audio signals 1815 with the wireless communication circuit1808. The audio circuit 1814 receives an electrical signal 1811 from amicrophone 1810 converting it into a form suitable for transmission bythe wireless communication circuit 1808. The signals received (audiosignals) from the wireless communication circuit 1808 by the audiocircuit 1814 are converted by the audio circuit 1814 into speakerelectrical signals 1813 to be reproduced a speaker 1813. It is known inthe art to use a single transducer as both a speaker and a microphone.If this approach is used, a separate microphone (e.g., 1810) and speaker(e.g., 1812) are not required.

The first two-way audio/video communication device 1800a communicatesvia the communication signals with a second two-way audio/videocommunication device 1800b. The second communication device 1800b may beidentical to the first communication device 1800a, or may be anequivalent device or devices, such as a conventional videophone.

It is within the purview of one skilled in the art to which the presentinvention most nearly pertains to implement monochromatic and colorimage sensors, using diffractive, refractive and/or combination optics,according to the techniques and arrangements set forth above. Certainmodifications that may become apparent from study of this disclosure areintended to be within the scope of the present invention. Accordingly,the present invention is not limited to the embodiments disclosed in theinstant specification, but is instead defined by the claims and theequivalents thereof.

What is claimed is:
 1. An image-sensing display panel, comprising:an LCDdisplay panel; a substrate having: an array of photosensitive elementsdisposed on a surface of the substrate; and an optically transmissivelayer above and contiguous with the array, wherein said transmissivelayer is capable of focusing light onto said array; wherein said LCDdisplay panel, and said substrate are aligned along the same opticalpath.
 2. An image-sensing display panel according to claim 1,wherein:said optically transmissive layer comprises a binary lenscapable of focusing light onto the array.
 3. An image-sensing displaypanel according to claim 1, wherein:the substrate is positioned behindthe LCD display panel along the optical path.
 4. An image-sensingdisplay panel according to claim 3, further comprising:means for causingthe LCD display panel to alternate between displaying an image and atransparent state.
 5. An image-sensing display panel according to claim4, further comprising:means for monitoring an output of the array ofphotosensitive elements only during periods of transparency of the LCDdisplay panel.
 6. An image sensing display panel according to claim I,wherein:the LCD display panel is positioned behind the substrate alongthe optical path.
 7. An image-sensing display panel according to claim6, further comprising:means for back-lighting the LCD display panel; andmeans for causing the LCD display panel to alternate between displayingand image and an opaque state.
 8. An image-sensing display panelaccording to claim 7, further comprising:means for monitoring an outputof the array of photo-sensitive elements only during periods of opacityof the LCD display panel.
 9. An image-sensing display panel according toclaim 1, wherein:the substrate is glass.
 10. An image-sensing displaypanel according to claim 1, wherein:the substrate is a ceramic material.11. An image-sensing display panel according to claim 1, wherein:thesubstrate is a transparent plastic material.
 12. An image-sensingdisplay panel according to claim 1, wherein:the LCD display panel andthe substrate are sized to approximately match the dimensions of asheet.
 13. An image-sensing display panel according to claim 12,wherein:a focal length and direction of aim of said opticallytransmissive layer are arranged such that light from an object held at aspecific distance from the substrate is focused onto the array ofphoto-sensitive elements.
 14. An image-sensing display panel accordingto claim 1, wherein:the substrate is positioned behind the opticallytransmissive layer along the optical path; and the LCD display panel ispositioned behind the substrate along the optical path.
 15. Animage-sensing display panel according to claim 1, wherein:the LCDdisplay panel is positioned behind the optically transmissive layeralong the optical path; and the substrate is positioned behind the LCDdisplay panel along the optical path.
 16. An image-sensing display panelaccording to claim 1, wherein:the optically transmissive layer ispositioned behind the LCD display panel along the optical path; and thesubstrate is positioned behind the optically transmissive layer alongthe optical path.
 17. An image-sensing display panel according to claim1, wherein:the LCD display panel, in an "opaque" state passes at leastone light frequency not visible to the human eyes; and thephoto-sensitive elements are sensitive only to the at least one lightfrequency passed by the LCD display panel in the "opaque" state.
 18. Animage sensing display panel according to claim 17, wherein:the at leastone light frequency passed by the LCD display panel in the "opaque"state includes an infra-red light frequency.
 19. An image sensingdisplay panel according to claim 1, further comprising:digitalprocessing circuitry; wherein: the digital processing circuitry includessubstantially all of the circuitry required to implement a digitalcomputer.
 20. A full page scanner, comprising:an LCD display panel; ansubstrate having an array of photosensitive elements disposed on asurface of the substrate; and an optically transmissive layer above andcontiguous with the array, wherein said transmissive layer is capable offocusing light onto said array; wherein:said LCD display panel, saidoptically transmissive layer, and said substrate are aligned along thesame optical path.
 21. A full page scanner according to claim 20,wherein:the LCD display panel and the substrate are sized toapproximately match the dimensions of a sheet.
 22. A full page scanneraccording to claim 21, wherein:a focal length and direction of aim ofsaid optically transmissive layer are arranged such that light from anobject held at a specific distance from the substrate is focused ontothe array of photo-sensitive elements.
 23. A full page scanner accordingto claim 22, wherein:the specific distance is zero, corresponding to anobject held against the substrate.
 24. A full page scanner according toclaim 20, wherein:the substrate is formed by depositing amorphoussilicon on a continuous sheet.
 25. A full page scanner according toclaim 24, wherein:the continuous sheet is metal.
 26. A full page scanneraccording to claim 20, wherein:ther substrate is formed by depositingpolysilicon on a continuous sheet.
 27. A full page scanner according toclaim 26, wherein:the continuous sheet is metal.
 28. A camera chipcomprising:an LCD display panel; a substrate having:an array ofphotosensitive elements disposed on a surface of the substrate; and anoptically transmissive layer above and contiguous with the array,wherein said transmissive layer is capable of focusing light onto saidarray; means for back-lighting the LCD display panel; and means forcausing the LCD display panel to alternate between displaying an imageand an opaque state; wherein: said LCD display panel, and said substrateare aligned along the same optical path; the LCD digital panel ispositioned behind the substrate along the optical path.
 29. A camerachip according to claim 28, wherein:alternation of the LCD display paneloccurs at a rate which is faster than the human eye can perceive.
 30. Acamera chip according to claim 29, wherein:the "opaque" state of the LCDdisplay panel is used to block light from the means for back-lightingfrom reaching the array of photosensitive elements.
 31. A camera chipcomprising:an LCD display panel; a substrate having:an array ofphotosensitive elements disposed on a surface of the substrate; and anoptically transmissive layer above and contiguous with the array,wherein said transmissive layer is capable of focusing light onto saidarray;means for back-lighting the LCD display panel; and means forcausing the LCD display panel to alternate between displaying and imageand a light transmissive state; wherein: said LCD display panel, andsaid substrate are aligned along the same optical path; the LCD displaypanel is positioned ahead of the substrate along the optical path.
 32. Acamera chip according to claim 31, wherein:alternation of the LCDdisplay panel occurs at a rate which is faster than the human eye canperceive.
 33. A camera chip according to claim 31, furthercomprising:means for controlling the degree of light transmissivity ofthe LCD display panel when it is in a light transmissive state.
 34. Acamera chip according to claim 33, wherein:the degree of lighttransmissivity is used to provide an "iris" function for the array ofphotosensitive elements.
 35. A camera chip according to claim 33,wherein:the degree of light transmissivity is used to provide a"shutter" function for the array of photosensitive elements.